Here my thoughts about sh1nee, rv and fx(I really hope I'm wrong)
J0nghyun suffered a car accident in 2013 (which we don't really know if was a *car* accident or some mk ultr4 reprogramming), sm made the other 4 members do a comeback without Jonghyun, when he came back he was blonde for the first time in his career (again, mk ultra hint) and 4 years later he passed away, the media claimed it was a suicide.
Sull1 leaft f(x) because apparently she was suffering from anxiety. She started to date a man much older than her, she was only 19 (this man even made sexual lyrics about her and I believe all the hate she had received started because of the time she was dating this man). Her last promotions with the group was in 2014 and in 2015 she officially leave the group, 4 years later she passed away, the media claimed it was a suicide. It is valid to mention Sulli had a blonde hair for the first time in the same year she passed away (last year) and she also suffered an accident before I think it was in 2015.
Now, we have red velvet: wendy suffered an accident last year and everything of this accident smells fishy to me. When she first appeared after the accident, she was blonde (I know she was blonde even before but still) and read a 'wizard of oz' story in some variety show. Now the other group members are taking picture withouth wendy (maybe cause she's recovering). I hope W3ndy isn't the next 'idol' to have an apparently suicide.
My final thoughts are that maybe it has a pattern here. A member leaves/suffer accidents and SM immediately starts to promove the group with the other 4 people. And I think shinee,fx and red velvet are somehow connected in the kpop 1illuminat1 agenda. The three groups have heavy symbolism, out of all sm groups they have this experimental image that maybe is an excuse to use concepts that aren't just weird but full of symbolism that young kpop fans don't understand (I'm an example of this even if I know about this filthy agenda, I still blind sometimes).